1. Field of the Invention
The present invention relates to a monitor, and more particularly, to an apparatus and method for sensing a rotary switch handling direction of a monitor.
2. Background of the Related Art
Generally, with development of computer software, high picture quality is required for a monitor. However, the monitor has several problems, such as balancing error, focusing error, and color purity error, in controlling and adjusting a screen. With a large sized screen of a monitor, the above problems are becoming more serious.
Accordingly, a monitor is provided with a compensating means that compensates such problems. As an example of the compensating means, a plurality of switches for adjusting a screen are provided in a predetermined region of the monitor. When the switches are provided to compensate errors for a plurality of screen adjusting modes, problems arise in that it is not easy for a user to handle a desired switch and the screen may incorrectly be adjusted.
To solve such problems, there has been provided a rotary switch that can select desired screen adjusting modes by allowing a user to rotate the switch. A related art rotary switch will be described with reference to FIGS. 1 to 3.
As shown in FIG. 1, the related art rotary switch includes a fixed disc 22 and a rotary disc 24. The rotary disc 24 overlaps the fixed disc 22 and rotates around a common shaft 26 relative to the fixed disc 22.
The fixed disc 22 includes a plurality of conductor pads 28 arranged to have the same angle around the common shaft 26. The rotary disc 24 includes two switches SWA and SWB. The switches SWA and SWB are fixed on the rotary disc 24 and arranged at angles with each other at a predetermined angle along a circular trace of the rotary disc 24.
A circuit configuration of the related art rotary switch will be described with reference to FIG. 2.
As shown in FIG. 2, the circuit of the related art rotary switch includes switches SWA and SWB, a resistor R1, a capacitor C, and a switch SWU. Each of the switches SWA and SWB has one end supplied with a power source of 5V through a resistor R2 and the other end commonly grounded. The resistor R1 and the capacitor C are connected in series between both ends of the respective switches SWA and SWB to form each loop of the switches SWA and SWB. The switch SWU is commonly grounded with the other ends of the switches SWA and SWB and has one end connected with a CPU of the monitor. The circuit of the related art rotary switch further includes a pulse generator (not shown) for respectively generating predetermined pulses when the switches SWA and SWB are in contact with the conductor pads 28.
The operation of sensing a handling direction of the related art rotary switch will now be described.
If a user rotates the rotary disc 24 in a predetermined direction, the switches SWA and SWB are in contact with the conductor pads 28 of the fixed disc 22. As a result, as shown in FIG. 3, output pulses xe2x80x98PAxe2x80x99 and xe2x80x98PBxe2x80x99 are generated by the pulse generator and then output through each switch.
At this time, since the switches SWA and SWB have a fixed relation position, as shown in FIG. 3, the output pulse xe2x80x98PAxe2x80x99 is generated by rotation of the rotary disc 24. Then, the output pulse xe2x80x98PBxe2x80x99 is generated at a time difference xe2x80x98t1xe2x88x92t2xe2x80x99 relative to the user""s rotary disc handling speed.
Meanwhile, if the user rotates the rotary disc 24 in a direction opposite to the predetermined direction, the output pulse xe2x80x98PBxe2x80x99 is generated and then the output pulse xe2x80x98PAxe2x80x99 is generated at a time difference relative to the user""s rotary disc handling speed. Therefore, it is possible to sense the user""s handling direction according to the phase difference between the output pulses xe2x80x98PAxe2x80x99 and xe2x80x98PBxe2x80x99.
The related art rotary switch has several problems.
First, in sensing the handling direction, the rotary switch and its linked circuits have complicated circuit configurations. Furthermore, since the handling direction of the rotary switch is sensed by the phase of the pulses, it is likely that error operation may occur due to delay of the phase.
Accordingly, the present invention is directed to an apparatus and method for sensing a rotary switch handling direction of a monitor that substantially obviates one or more problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide an apparatus and method for sensing a rotary switch handling direction of a monitor in which a simple configuration can be obtained and accuracy in sensing a handling direction can be enhanced.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, an apparatus for sensing a rotary switch handling direction of a monitor includes a rotary switch for outputting voltage levels varied correspondingly depending on a user""s handling direction, and a microcomputer for storing the voltage levels output from the rotary switch and comparing the voltage levels with a previously stored voltage change/handling direction table to determine a handling direction of the rotary switch.
In another aspect of the present invention, in a method for sensing a rotary switch handling direction of a monitor having a rotary switch and a microcomputer, the rotary switch having variable output levels depending on a user""s handling direction, the method includes the steps of successively reading out and storing, at a microcomputer, the voltage levels output from the rotary switch depending on the user""s rotary switch handling direction for predetermined number of times, and comparing the stored voltage levels of the rotary switch, at the microcomputer, with a previously stored voltage change/handling direction table to sense a handling direction of the rotary switch.
It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.